Service on a defect Soldano SP-77
On the workbench, a Soldano SP-77 in a nice cosmetic condition. It produces a very low, ugly distortion on both channels.
There are no obvious signs of anything wrong on the inside.
However, a voltage control on some critical points spotted the problem. The 100K resistor R24 is no longer conducting.
A photo of the circuit board’s bottom side.
After replacing the defective R24 resistor and the dried-up electrolytic caps, it is now functioning properly.
